Molded articles each comprising reinforcing fibers and a thermoplastic resin are lightweight and have excellent mechanical properties and, therefore, have been used widely in applications including applications to sporting goods, aerospace applications and general industrial applications. In the molded articles, the reinforcing fibers used are metal fibers such as aluminum fibers and stainless steel fibers, organic fibers such as aramid fibers and PBO (polyparaphenylene benzoxazole) fibers, inorganic fibers such as silicon carbide fibers, carbon fibers and the like. Among these reinforcing fibers, from the viewpoint of the balance among specific strength, specific stiffness and lightweight properties, carbon fibers are preferred, and polyacrylonitrile (PAN)-type carbon fibers have been particularly preferably used.
Because of the excellent specific strength and specific stiffness of carbon fibers, molded articles reinforced with carbon fibers have excellent lightweight properties and bending strength. Therefore, the molded articles have been used widely in various fields including housings for electronic devices and automotive members. However, in applications for electronic device housings, the amount of heat generated in each of the electronic components tends to increase due to the improved performance of the electronic components. In those situations, in molded articles such as housings, it has been demanded to improve heat conductivity as well as lightweight properties and bending strength.
For example, as a molding material having excellent fiber dispersibility, a molding material in which a thermoplastic resin is adhered to composite reinforcing fiber filaments (see, e.g., Japanese Patent Laid-open Publication No. 2012-56232) is proposed. As an electrically conductive resin composition having excellent heat resistance, stiffness and dimensional accuracy, an electrically conductive resin composition composed of a thermoplastic resin, carbon fibers and graphite having a scaly form (see, e.g., Japanese Patent Laid-open Publication No. 10-237316) is proposed. As a heat-conductive polycarbonate resin composition having excellent impact resistance, heat conductivity and flame retardancy, a heat-conductive polycarbonate resin composition composed of a polycarbonate resin, carbon fibers and phosphorus-containing flame retardant agent (see, e.g., Japanese Patent Laid-open Publication No. 2014-177547) and the like are proposed.
However, in the techniques disclosed in JP '232, JP '316 and JP '547, there is the problem of insufficiency in bending strength and heat conductivity. It could therefore be helpful to provide a fiber reinforced thermoplastic resin molded article having excellent bending strength and heat conductivity.